Impact-type material handling clam-shell apparatus



Feb. 28, 1956 s H 2,736,444

IMPACT-TYPE MATERIAL HANDLING CLAM-SHELL APPARATUS Filed July 24. 1953 3 Sheets-Sheet l 33 IO /9 g P 32 k III. lh I lh i III INVENTOR.

Luke E. Smith 7 ATTORNEY Feb. 28, 1956 L. E. SMITH 2,736,444

IMPACT-TYPE MATERIAL HANDLING CLAM-SHELL APPARATUS 3 Sheets-Sheet 2 11 H I II I 1 MHHWI I MIH ZI Filed July 24. 1953 INVENTOR.

Luke E. Smifh ATTORNEY L. E. SMITH Feb. 28, 1956 IMPACT-TYPE MATERIAL HANDLING CLAM-SHELL APPARATUS Filed July 24.

3 Sheets-Sheet 3 INVENTOR.

Luke E. Smith ATTORNEY United States Patent O IMPACT-TYPE MATERIAL HANDLING CLAM-SHELL APPARATUS A Luke E. Smith, Denver, Colo.

Application July 24, 1953, Serial No. 370,054

2 Claims. (Cl. 214657) This invention relates to material handling equipment and the methods of operation thereof, and particularly it relates to crane or boom-type equipment including jawed material handling equipment, such as, clamshell buckets, grapples, tongs, forks, and like gripping devices.

Clamshell power buckets are used extensively for moving earth and other material which is relatively loose or may be loosened without great difficulty. However, in many applications where clamshell buckets would greatly facilitate the effectiveness of the operation, the material is too hard to scoop up in the normal operation of the clamshell. In other situations, for example, when it is desired to move a'rock or other heavy object, the normal drop of the clamshell will not result in sufficient pressures to enable the bucket to lift the object. Accordingly, it is an object of this invention to provide a material handling device including an improved arrangement for facilitating the initial handling or gripping of the material to be moved.

Another object of this invention is to provide a power device of the plural jawed gripping type including an improved arrangement for securing an effective grab about the material to be moved.

It is another object of this invention to provide an improved and novel method of operation of an improved material handling device.

It is a further object of this invention to provide an improved bucket of the clamshell type in which the jaws thereof may readily be driven into position about the material to be moved.

It is still another object of the present invention to provide an improved material handling device, including the clamshell and/or grapple type having an improved closing mechanism, and a method of operation thereof.

Still another object of the present invention is to provide a bucket of the clamshell type having a novel operating mechanism which provides very fast, efficient bucket closing capable of picking up a full bucket load.

Further objects and advantages of this invention will i become apparent as the following description proceeds and features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

In carrying out the objects of this invention in one embodiment thereof, a power assembly of the multiple jaw type having multiple scoops or grapple teeth is suspended from a shovel boom or elongated support which is pivoted on a crane boom. A head member is rigidly secured to the lower end of the support and the scoops of the assembly, which are center pivoted together in the usual manner, are secured to the head by pivoted links which afford opening and closing movement of ,the clamshell when the center pivot of the scoops or grapple teeth is lowered and raised respectively. A heavy weight on the upper surface of the head provides means for applying a 2,736,444 Patented Feb. 28, 1956 ice upward or Vertical displacement, so that the jaws will take a full measure of the position around the material handled. The weight is so distributed on the gripping edges of the assembly, that on closing the jaws, the center pivot tends to remain stationary and the head drops on closing the jaws pushing the jaws deeper into the material. With standard devices, for example, a standard clamshell, the weight is interconnected with the pivot, so that the weight is raised and withdrawn from the gripping edges on closing the bucket. The present invention, therefore, provides a novel method of operating such device more efiiciently and faster than the prior art devices.

In order to drive the scoops or jaws, for instance a clamshell, of a bucket deeply into the ground or about the material to be handled, the heavy weight is slidably mounted on the support for movement toward and away from the head. In its lowermost position the weight engages the head and provision is made to secure the Weight to the head if desired. The weight is independently connected to lifting or hoisting cables and may be raised and then dropped against the head to deliver downward impacts to the head and to the gripping edges of the device. Thus when the bucket is in its open position resting on earth or other material the jaws may be driven into the material by the hammering effect of the weight, and on closing the weight maintains the jaws in the driven position. This greatly facilitates the handling of material which would otherwise be diflicult to move.

With the weight secured to the head, as by bolting, etc., or by merely having the weight resting on the head,

: an improved closing mechanism is provided. A material handling assembly such as a clamshell type bucket,'a grapple, and the like, may be attached to the head to utilize the novel operation. The combination of weighted head and the linkages to jaws provides a device which will close faster and pick up bigger loads than the present conventional devices. The mechanism provides means for fast closing of the jaws without substantially lifting the pivot or the lips of the jaws. The linkages distribute the weight on the head to the gripping edges of the jaws,

so that weight is 'efifectively applied throughout the placement, and taking a full measure of material. With clamshells or grapples the full force of the weight on the jaws provides gripping force not available in the prior art devices.

The weight resting on the head, or a heavily weighted 1 head may advantageously be used to control the depth of digging of a clamshell bucket. Conventional clamshells must be dropped onto the ground to start the jaws digging, as the closing mechanism substantially raises the bucket and/ or the bucket weight. With the present device, the

, weight may be held in one position and the jaws closed against it. This limits the depth of digging of the jaws, and further, provides force for digging to the desired level. The bucket is not dropped to start the bucket edges into the ground, as the weight supplies the digging force. The bucket jaws may be closed as fast as the haul back mechanism permits, and the bucket will take a full measure of material each closing.

The weight is independent of the closing mechanism, whereby during the closing movement, the weight may be used as a hammer, resting on the head, or not in contact with head at all. This provides a new theory of operation, and provides improved and novel results.

For a better understanding of the invention reference may be had to the accompanying drawings in which:

Fig. 1 is a side elevation view of a bucket embodying the invention mounted on a power boom;

Fig. 2 is an enlarged plan view of the head assembly of the boom;

'Fig. 3 is a side elevation of the bucket assembly with the scoopsin their open position;

Fig. 4 is a side elevation view of the bucket assembly with the bucket rotated 90 from its position as shown in Fig. 1;

Fig. 5 is a view of the modified arrangement of the invention showing the bucket assembly suspended from a crane hoist;

Fig. 6 is a front elevation view of the assembly of Fig. 5;'and

Fig. 7 is a fragmentary detail of the bucket support taken along section lines 77.

In Fig. 1 a power bucket assembly 10 is pivotally mounted on a crane power boom 11 so that it depends therefrom and may be raised and lowered by operation of the boom to pick up material, such as earth, to be handled. The crane boom is secured to a crane, which may be mounted on a tractor, truck, and the like, for moving the bucket from point to point. The bucket assembly 10 comprises a head 12 and a bucket having two scoops 13 pivoted about a common shaft 14. The scoops 13 are secured to the head 12 by links 15, four in'number, one at each corner of the head 12 which is of rectangular form. The links are pivotally connected to lugs 16 depending from the head 12 and lugs or arms 17 on the scoops 13. The shaft 14 is secured to the lower end of a guide member 18 which extends upwardly within a hollow guide member or support 19. The guide 19 is rigidly secured to the head 12. At its upper end the guide 19 is pivoted on a sheave or pulley shaft 20. The guide 19 is secured to two hangers or arms 21 welded or otherwise suitably secured to the top thereof, the hangers are secured to bearings 22 journalled on the shaft 29 as shown in Fig. 2. The member 18 slides within the member 19 which acts as a guide for member 18 for opening and closing the bucket. The bucket is opened and closed by operation of a haul back cable 18a. The haul back cable passes through member 18 and over a center sheave 23 in the head of the boom on the shaft 20. The haul back cable operates to close the bucket when it is lifted to raise the pivot 14 with respect to the head 12. The manner in which a clamshell operates being well known in the art.

During operation the clamshell is moved to its open position as indicated in Fig. 3 and is dropped or lowered to the earth or other material to be handled. The bucket is then closed by operation of the haul back cable, and, thereafter, the closed bucket with its lead of earth or other material is lifted by raising the boom. The boom is then moved to a side position for dumping. The power boom may be employed to lower the bucket force-ably against the-earth, and for this purpose the sheave assembly on the shaft is mounted in a stirrup block or head piece 25' having bearings 26 for the shaft 2t and which is pivotally attached to the end of the boom 11 by a bolt 27. The block 25 has an extension on the upper side thereof, provided with a bumper plate 23 which. engages a bumper block 29. The block 29 is secured to the top of the boom 11 and the block 29 and plate 28 are secured together by bolts 36. It will thus be apparent that when the bucket is driven against the ground the shock is taken up by the block 29 as the head 2-5 tends to rotate about the pivot 27.

It has been found that some materials are sufliciently packed-or solid that it is impractical to handle them even with the power boom type of clamshell bucket. Nevertheless, there are many applications for the clamshell bucket which make it desirable to employ this type of power boom and power bucket combination in connection with these materials which are hard to handle. Another application, where the conventional bucket is not entirely suitable, is the lifting of large objects which are located in positions or .in material where it .is difficult to drop the bucket about the object and thereafter pick it up by the action of a standard clamshell, for example, rocks buried in hard earth. In order that the scoops of the bucket may be driven in position about the material so that the jaws of the clamshell power bucket may securely grip such buried objects, and the like, a hammer assembly is provided to drive the open jaws downward. The assembly illustrated includes a weight 32, which is slidably mounted on the support member 19, which may be raised away from the head 12. A lifting plate 33 is attached to the weight 32 by bolts 34, and is provided with lugs 35 to which hoisting cables 36 are attached. The hoisting cables pass over the outer sheaves 37 of the head assembly of the boom and by hoisting the weight and then dropping it a heavy impact or hammer action is applied downwardly against the head. When the bucket is in its position as shown in Fig. 3 this downward impact serves to hammer the jaws of the bucket into the material on which the bucket is resting. This hammering action may be continued by repeated impacts delivered by the weight 32 until the jaws of the bucket have assumed the desired position for handling the material. For example, if a rock is to be lifted the jaws may be driven into the earth around the rock so that asecure grip on the rock is acquired, and the weight provides tremendous gripping force so that the rock may be lifted easily without danger of slipping. in other applications where the earth or material to be handled is hard, the bucket jaws may be driven into the material. The bucket may, also, be closed in a desired position by the hammering action.

The weight 32 is preferably provided with a notch or keyway, and a keyway 8 is secured to the outer surface of the support 19 to accommodate a spline or key 9 secured to guide member 18 so as to prevent rotation of the weight 32 about the support 19. The attaching plate 33 may be provided with a large number of bolt holes so that it may be attached in a number of angular positions. In a similar manner, the support 19 is attached to the upper end of the head assembly by a flanged connection 38 and 39, so that its angle with respect to the boom may be adjusted. It is thus apparent that the angular position of the bucket assembly with respect to the boom may be shifted by Shifting the attaching plate 33 and the flange assembly 38, 39. In Fig. 4 the bucket assembly is shown shifted to a position from that in Figs. 1 and 2. In Fig. 3 the weight 32 is shown in raised position in full lines and in dotted lines in its lowered position after'it has delivered an impact to the head 12. It is, therefore, apparent that the shovel assembly may be used at any desired angle with respect to the boom, and that the repeated impacts may be delivered regardless of the position of the shovel assembly on the boom.

This typeof power assembly thus provides an arrangement which makes it possible to employ a new method of operation for such assemblies. It will be apparent that the arrangement for delivering repeated downward impacts to the gripping or digging edges of the assembly will make it possible to operate the assembly more effectively and more quickly regardless of the characteristics of the material to be handled. For example, in using the clamshell as digger, the use of the repeated impacts from the hammer, or the heavily weighted head makes it possible to close the bucket more quickly than would otherwise be possible for a given loading of the bucket. By hammering the bucket assembly into the material to be lifted, it is possible to take a full bucket each time the bucket is closed. Also, by using the hammer 32 as a dead weight, a new method of operation is provided, which is fast and efficient.

The clamshellbucket assembly illustrated in Figs. 5 and 6 is essentially :the same as that shown in the preceding figures, except that it :is suspended from a crane hoist rather than from a power boom. Corresponding partsof the assemblyof'Figs. '5 and o have been designatedlby the same numerals as those employed in Figs. 1 to 4, inclusive. In this assembly the vertical support 19, instead of being attached to the boom through the flange connection 38, is suspended with the bucket on the haul back cable 18a which is attached to the shaft 14. The haul back cable 18a or closing line passes from the shaft 14, through the hollow guide member 13 and the support 19, and thence over a sheave 40 at the top of the crane boom 41. In operation, this assembly is essentially the same as that of Figs. 1 to 4 inclusive, except that no pressure can be applied through the power boom. The provision of the weight 32 connected with the hoist cables makes it possible to drive this type of clamshell into the material to be handled, so that a full load may be taken out at each operation of the equipment.

When the device is used without the hammer effect, the weight 32 is maintained as a dead load on the head 12. The weight may be secured by bolting, etc., to the head, or by merely having the weight resting freely on the head. When operated with the weight on the head, or where a shovel is provided with a weighted head, the jaws of the bucket may be rapidly closed without substantial upward vertical displacement, due to the effective distribution of the weight, through links 15, 16 and 17 to the edge or lip of the bucket jaws. Thus, when the weight 37 (shown in dotted lines, Fig. 3) is resting on the head with the jaws open, the effective weight is on teeth 13a on the lip of bucket jaws 13. When the haul back cable 18a is moved upwardly, the shaft 14 is raised, and the Weighted head drops to substantially hold the bucket jaws in a smooth arc of rotation to closed position. The jaws may, therefore, be rapidly closed and still take a full measure of material. The weight distribution also provides a tremendous gripping force of the jaws, and, further, provides means for secure gripping due to closing without lifting. The weight is eifectively applied to the gripping edges of the jaws throughout the closing action, so at any point during the closing maximum grip of the jaws is applied.

It will readily be apparent that this arrangement for delivering repeated impacts in a downwardly direction to facilitate the operation of power shovels may be applied to other types of equipment than that illustrated. Obviously, it may be applied to the so-called orange peel bucket which is a modified form of the clamshell, or grapples, or tongs, or forks, or the like.

While this invention has been described in connection with a specific type of power bucket, other applications will readily be apparent to those skilled in the art. Therefore, it is not desired that the invention be limited to the particular forms illustrated and described and it is intended by the appended claims to cover all modifications within the spirit and scope of the invention.

I claim:

1. Material handling equipment comprising a bucket of the clamshell type including a plurality of scoops depending from a connecting member and pivoted thereon, means attached to said connecting member for lifting and closing said bucket, a first head member above said bucket and having an opening to afiord passage of said lifting means, a plurality of bars each pivoted on said head and on a respective scoop of said bucket remote from said connecting member, a second head member reciprocally disposed above said first head member, spline means for preventing relative rotation of said first and second head members, a readily detachable plate secured to the top of said second head member, a pair of lifting cables attached to said plate and arranged to maintain a predetermined angular position of said plate about a vertical axis, means for attaching said plate to' said second head member in any one of a plurality of angular positions whereby the angle of said clamshell with respect to said predetermined position may be adjusted about its vertical axis, and means utilizing said cables for lifting said second head member from said first head member whereby it may be released and dropped as a hammer to strike said first head member and drive the lips of said bucket into the material to be handled, the force of the hammer blows being transmitted through said bars to said bucket.

2. The combination with material handling apparatus inclusive of a boom, of a material moving assembly suspended from the boom and including a rigid guide member pivoted on the boom, a plural jawed bucket carried at the lower end of said guide member, means for imparting opening and closing movements at the jaws of the bucket, a weight slidably mounted on said guide member for movement toward and away from said bucket, spline means for preventing relative rotation of said weight and said bucket about the longitudinal axis of said guide member, means for applying said Weight as a hammer to impart downward impact to said bucket at any jaw setting thereof, said last mentioned means including a pair of lifting cables secured to an attaching member on either side of said guide member, and means for securing said attaching member to said weight in any one of the plurality of positions about the vertical axis of said guide member to adjust the position of said bucket with respect to the boom.

References Cited in the file of this patent UNITED STATES PATENTS 528,579 Williams Nov. 6, 1894 850,356 Desy Apr. 16, 1907 1,051,994 Gardner Feb. 4, 1913 1,218,826 Armstrong Mar. 13, 1917 1,229,600 Fogarty June 12, 1917 1,236,418 Fogarty Aug. 14, 1917 1,812,925 Buckland July 7, 1931 2,230,498 Loos et al Feb. 4, 1941 2,594,720 Beck, Jr. Apr. 29, 1952 FOREIGN PATENTS 1,741 Great Britain May 16, 1874 

